Conversion of hexachloroacetone into trichloroacetic and chloroform and separation and recovering of trichloroacetic acid



United States Patent "Office 2,695,918 Patented Nov. 3'0, 1954CONVERSION OFHEXACHLOROACETONE INTO `TRICHLOROACE'TIC AND CHLOROFORM ANDSEPARATION AND RECOVERING OF TRI- CHLOROACETIC ACID ApplicationSeptember 4, 1952, Serial No. 307,878

16 Claims. (Cl. 2611-539) This invention relates to the manufacture andrecovery r of trichloroaceticacid and, more particularly, refers to a :1new and improved method, of converting hexachloroacetone totrichloroacetic acid and chloroform and the -`separation and recovery oftrichloroacetic acid.

The conventional method for the preparation of tri- .chloroacetic acidis by oxidation of chloral with furning nitric lacid, permanganate orpotassium chlorate. These ,procedures have several disadvantagesincluding destruction of a material'portion of the charging material dueto the use of strong oxidizing agents, low yields of desiredtrichloroacetic acid, expensive operation due in part tocostlyreactants, and difficulty in separating and recoveringtrichloroacetic acid due to the presence of the various contaminants inthe reaction products resulting from side reactions.

. One object of the present invention is to provide an eti'cient processfor converting hexachloroacetone and recovering trichloroacetic acid.

- Another object of .this invention is to provide an economical processfor producing high yields of high purity trichloroacetic acid andchloroform.

A further object of the present invention is to provide animprovedmethod of acidifying a salt of trichloroacetic acid and:extracting and recovering the resultant trichloroacetic` acid.

'Further objects and advantages will be apparent from the followingdescription and drawing.

In accordancewith the present invention, conversion ofv'hexachloroacetone may be accomplished by intimately mixinghexachloroacetone with an aqueous solution of van alkaline metalcompound at a temperature below 60 5C.,\desirablynot below 0 C.,preferably 25-30 C., for a suflicient length of time to effect scissionof the hexa- `chloroacetone moleculerand reaction with the aqueousalkaline metal compound to produce a metal salt of trichloroacetic acidand chloroform. Scission of hexachloroacetone and reaction with sodiumhydroxide solution to produce chloroform and a solution of sodiumtrichloroacetate, may be exemplified by the following equation:

CClaCOCCls-l-NaOH-aCClsCOONa-l-CHCla Reaction productscomprising anaqueous solution of a metal salt of trichloroacetic acid (ClaCCOONa orCClaCOOK) may lthen be aciditled with excess sulfuric acid in an amountsufficient to liberate trichloroacetic acid and form a bisulfate.Aciditication of sodium trichloroacetate solution with sulfuric acid toliberate the `trichloroacetic acid, may be exemplified by the followingequation:

The resultant reaction products, upon standing, separate into an upperlayer of aqueous bisulfate solution and a lower layer of chloroform`containing trichloroacetic acid dissolved therein; the lower layer maybe withdrawn and the chloroform kstripped from the mixture leavingsubstantially pure trichloroacetic acid as bottoms. If desired, some ofthe stripped chloroform may be returned for admixture with the upperlayer which contains small amounts of trichloroacetic acid for thepurpose of recovering by extraction the trichloroacetic acid in thebisulfate layer.

11 to the reactor.

The accompanying drawing is a diagrammatic flow sheet illustrating onemethod ofpracticing the invention.

Referring to the drawing, hexachloroacetone, a colorless liquid boilingat 202-204 C. at atmospheric pressure, from any suitable external sourceor which may be prepared by the method described in application SerialNo. 92,772, .filed May 12, 1949, `now Patent No. 2,635,117, is chargedthrough line 1 into reactor 2 which may bean lempty enclosed chamber,preferably constructed of stainless steel and provided with a coolingcoil 3 and condenser 4. An aqueous solution of a metal alkaline materialsuch as sodium hydroxide, `potassium hydroxide or soda ash inapproximately molal proportions of alkaline material tohexachloroacetone, is slowly added through line 5 at a rate suflicientto maintain a reaction temperature of about 25-30 C. Since the reactionis exothermic, a cooling medium such as water passing through coolingcoil 3 aids in maintaining the temperature of the reaction mixture.Intimate Contact between the reactants is assured by means of agitator6. Care should be taken not to exceed above about 60 C. since sodiumtrichloroacetate, one of the products ofthe reaction decomposes above 60C. At temperatures below about 0 C., the reaction is unduly long andfurthermore, operating difficulties may be encountered at lowtemperatures due to solidiiication of the hexachloroacetone. As apractical matter, the operation may be conveniently carried out atsubstantially atmospheric temperature, i. e. 25-30. C. VApproximatelyone hour is required for feeding the aqueous sodium hydroxide intoreactor 2. After NaOH has been added, agitation is continued for anotherhour or until titration of a sample of water layer shows completeconsumption of the NaOH. During the course of reaction, chloroform is'liberated, a portion of which vaporizes, passing up through vaporline 7into condenser 4 wherein the chloroform vapor is cooled and ycondensedby indirect heat exchange with water flowing in through line 8 and `outthrough line 9 and the chloroform condensate returned through-liquidreflux line The 'reflux condenser 4 thus aids in maintaining thetemperature of reactants in reactor 2 and further, is a means ofretaining the chloroform in the reaction products to serve later as anextraction medium.

If Lthe products of reaction, chloroform and aqueous sodiumtrichloroacetate, are' allowed to' settle, they will separatev into anupper 'layer' of aqueous sodium trichloroacetate and `a `lower layer ofchloroform. If it is desired to separately recover the chloroform andsodium -trichloroacetate as vend products,then the lower layer ofchloroform is rst withdrawn from the bottom of reactor 2Hthroughlinesf12, valve 13,I line 1'4 and valve 15 to storage and then the upperlayer of aqueous sodium trichloroacetate withdrawn through lines 12 and14 and `directed to storage or, if desired, sent to an evaporator torecover solid sodium trichloroacetate.

However, if it is desired to produce trichloroacetic acid as an endproduct, it is unnecessary to settle and separate the reaction productsin reactor 2 and, in fact, it isadvantageous to retain the chloroform inadmixture with the reaction products. The reaction products in reactor2, without separation, are withdrawn through line 12, valve 13 andforced by pump 16 through line 17 into acidiier and extractor chamber18, similar in construction to reactor 2 and equipped with agitator 19,cooling coil 21 and reflux condenser 22.

Sulfuric acid of about -95% concentration, in approximately molalproportion to the amount of sodium trichloroacetate is gradually addedto the CClsCOONa-CHCls reaction products in acidifier` 18 while rapidlyagitating and cooling the mixture to maintain a temperature below about60 C., preferably about 25-30 C. The acidification reaction is quiterapid and completed by the time all the acid is added, a period of aboutone hour. To insure completion of reaction, agitation may be continuedfor an additional time of say about one-half hour. Agitation is thenterminated and the reaction mixture in reactor 18 permitted to settle,whereupon it separates into an upper layer of aqueous sodium bisulfateand a lower lavergf trichloroacetic acid dissolved in chloroform.Approximately 95% of the trichloroacetic acid is dissolved in the lowerchloroform layer. The remainder of trichloroacetic acid, usually lessthan remains in the upper sodium bisulfate liquor layer. i

An important feature of the process resides in carrying theacidification of the sodium trichloroacetate to the b1- sulfate statethereby producing reaction products in liquid state free of solidprecipitates which cause difficulty in separation of desiredtrichloroacetic acid and chloroform products and loss of these products.Acidication of sodium trichloroacetate solution in the proportion of 2mols of sodium trichloroacetate to 1 mol of sulfuric acid, resulted in a3-phase system composed of an upper aqueous layer, a lowertrichloroacetic-chloroform layer and solid sodium-sulfate as illustratedby the following equation:

ZCISCCO ONa-I-HzSOi ZCISCCOOH-i-NazSOtl The sodium sulfate salt settlesto the bottom and impedes the extraction of the trichloroacetic acid tosuch an extent that even after four extractions with chloroform, onlyabout 85% of the trichloroacetic acid was recovered.

Acidification of the sodium trichloroacetate with HCl according to thefollowing equation, resulted in a- 3-phase system composed of two liquidlayers and solid NaCl at interphase.

The bottom layer contained only about 82% of the trichloroacetic acidand even after four extractions with equal volumes of chloroform, atotal of about 92-93% trichloroacetic acid was recovered.

From the foregoing, it will be evident that carrying the acidificationof sodium trichloroacetate to the bisulfate stage has numerousadvantages including elimination of solid precipitate which carries withit valuable occluded product and causes diiculty in separation of theproduct, ease of separation of the liquid layers, and greater recoveryof the trichloroacetic acid and chloroform with fewer extraction steps.In addition, the sodium bisulfate has a much higher market value thaneither sodium chloride or sodium sulfate.

Although the acidification reaction has been described as carried out inthe presence of the preferred solvent, chloroform, other solvents whichare liquid, immiscible with water and in which trichloroacetic acid issoluble, e. g. toluene, monochlorobenzene, carbon tetrachloride, orpetroleum naphthas, may be employed.

The lower layer in acidier 13 of chloroform having dissolved thereinover 95% of the trichloroacetic acid, is withdrawn through line 24,valve into chloroform stripper 26 which may be any suitable conventionalevaporator or column equipped with the usual reboiler section to effectvaporization of the low boiling chloroform from the trichloroaceticacid. The chloroform vapors are released from the top of column 26through line 27, condensed, and directed to storage through line 28 andvalve 29. The chloroform produced is quite pure and after minorconventional purification may even be employed for drug purposes. Thetrichloroacetic acid, which is also quite pure, is discharged from thebottom of column 26, through line 31 and valve 32, directed to storageor, if desired, may be sent to another tank to crystallize.

Although the upper sodium bisulfate liquor layer in acidilier 1Scontains less than 5% of the total trichloroacetic acid, an additional2-3% trichloroacetic acid may be recovered by introducing into acidier18 a volume of chloroform equal to the volume of sodium bisulfate liquoreither from an external source through lines 33 and 34, or recyclingchloroform released from chloroform stripper 26 through line 35 andvalve 37. The chloroformsodium bisulfate liquor is then agitated bystirrer 19 to insure intimate contact, the mixture permitted to settleand separate into a lower chloroform layer, and the chloroform layerdirected via line 24 and valve 25 to chloroform stripper 26 for theseparation of the mixture into chloroform and trichloroacetic acid. Theremaining sodium bisulfate liquor may then be discharged from acidifier18 and directed through line 37 and valve 38 to a conventionalevaporator to recover solid sodium bisulfate.

The operations in reactor 2 and acidier 1S may be carried out undersubstantially atmospheric pressure; superatmospheric or subatrnosphericpressures add to the cost of the operation and are unnecessary. Also, itwill be noted that the reactions in reactor 2 and aciditier 18 are at alow temperature, substantially atmospheric, re sulting in greater easeof operation, in less expensive construction of apparatus and, ingeneral, greater efficiency as compared to high temperature, highpressure reactions.

Although the process has been described as being carried out in abatch-wise manner, it is adaptable to continuous operation. The reactorfor continuous conversion of hexachloroacetone may be constructed of atower packed with distributing bodies and cooled by water circulationthrough a jacket. Hexachloroacetone may be fed into the body of liquidreactants in the tower at a point near the top. Aqueous sodium hydroxidemay be introduced near the base of the tower thereby causing continuouscountercurrent reaction between the aqueous NaOH and hexachloroacetone.The rate of feed of the reactants should be regulated to permit aresidence time in the tower of about 2 hours. Chloroform settling at thebottom of the tower and aqueous trichloroacetate collecting at the topof the tower may be continuously withdrawn from the tower and thecommingled streams transferred to a continuous acidifier which may be acolumn similar to the reactor, with sulfuric acid fed into the tower ata point near the top and reaction products from the reactor introducedat a point near the base of the tower. The upper layer of sodiumbisulfate and lower layer of chloroform-trichloroacetic acid may becontinuously withdrawn from the tower and then directed to a settlingtank to insure sharp separation between the two layers. Alternatesettling tanks are desirably employed to insure continuity of operation.The lower layer of chloroformtrichloroacetic acid may then be directedto a falling film continuous type stripper from which chloroform will beremoved as overhead and trichloroacetic acid as bottoms from thereboiler. The bisulfate liquor from the settling tank may be sent to acontinuous countercurrent-extraction column wherein it will contactcondensed chloroform from the continuous stripper. The treated sodiumbisulfate liquor may then be directed to an evaporator for recovery ofsolid sodium bisulfate. The extract may be sent to the falling lmcontinuous stripper for separation of the chloroform from thetrichloroacetic acid.

The following example illustrates the invention.

A reactor constructed of stainless steel and equipped with cooling coil,agitator, temperature recorder, reflux condenser for chloroform andbottom takeoff as illustrated in the drawing, is charged with 3,322 lbs.of pure hexachloroacetone and, while cooling and agitating, 3,510 lbs.of 20% by weight NaOH solution are run in slowly to the reactor at arate sufficient to maintain a reaction temperature of 25-50 C.Approximately one hour is required. After NaOH has been added, agitationis continued for another hour.

The reaction product mixture comprising an aqueous solution of sodiumtrichloroacetate and chloroform totaling 5,832 lbs. is sent to anacidifying and extracting chamber similar in construction to the reactorand also provided with reflux condenser, cooling coil, agitator,temperature recorder and bottom draw-off line. With cooling and withrapid agitation, 1,322 lbs. of 93% sulfurie acid are fed into theaciditier at a rate sufficient t0 maintain a temperature of 25-30 C. Bythe time all the acid is added, most of the trichloroacetic acidliberated is in the chloroform bottom layer which is then removed. Then,1,322 lbs. more chloroform are added to the acidifier chamber to extractan additional amount of trichloroacetic acid from the bisulfate layerremain-v ing in the chamber. In all, 97.5% of the trichloroacetic acidis extracted in these two treatments. 95.4% being removed in the firstand 2.1% in the second. The chloroform-trichloroacetic acid extract issent to a chloroform stripper wherein chloroform is vaporized from thetrichloroacetie acid. The sodium bisulfate solution remaining in theacidifier is directed to an evaporator to obtain solid NaHSO/i. Thetrichloroacetic acid product is very pure and contains only a trace ofdichloroacetc acid and a little NaHSOi. The chloroform product is ofvery pure grade and, after redistillation to remove small amounts ofimpurities, is suitable for drug use. The NaHSO4 solution resulting fromthe acidification of the Sodium trichloroacetate solution contains about40% NaHSO4 and is supersaturated with respect to the anhydrous salt andwill crystallize after standing several hours.

Althoughcertain preferred'em'bo'diments ofthe invention have benldisclosed for *purpose of illustration` 1t will be evident that'various 'changes and' modifications" may bemade thereinwithoutfdepartingrfrom the scopeff and spirit 'of the invention.

Weclaim: i

l. A process forthe conversion-` of hexachloroacetone Iintotrichloroaceticacid and` chloroform which com prises `admixing asthe solereactants hexachloroacetone with an aqueous alkaline1solution of`an alkali metal compound at a temperature below about\601lC. for asufficient lengthof time to eifectscission of the hexasulfunicuacid `inan amount lsuiiicientto liberate trichlorov aceticacid andform lsodiumbisulfate 'therebyproducingn acidificationreactionprodutts in the liquid`state free 'of solidy precipitates.'V

chloroacetone molecule and reaction with the -alkali'f metal compound inthe proportion `of one mol hexachloroacetone to about one mol equivalent'of alkali metal compound to `produce-a metal salt of-trichloroaceticacld and chloroform and Iacidifying themixture -ofithe Imetal saltoftrichloroacetic acid andl chloroform by' reaction@ with excess sulfuricacid in an` amount sufficient `to lib"-` erate `trichloroacetic acidland form a bisulfate thereby producing acidification reactionproductsrin'the` liquid state free of solid` precipitates.

2. A process for theconversion of hexachloroacetone into trichloroaceticacid and chloroform which comprises intimately mixing as the sole`reactants hexachloroacetone with` an alkaline aqueous solution of analkali' metal Vcompound at a temperature below 60` C. for a suiiicientlength of time' to effect lscission of thehexachloroacetone molecule andreaction with theaqueous alkali metal compound in the proportionr of onemol hexachloroacetone to about one mol equivalent of alkali' metalcompound to'produce an'aqueous solution of Va metal saltV oftrichloroacetic acid and chloroform, and acidifying the mixture of theIaqueous solution `of metal salt of a trichloroacetic-acid andchloroform byfreaction at a temperaturebelow 60 AC. 'with excesssulfuric acid in an amount'suiiicient to*liberate'trichloroacetic acidand form a bisulfate'thereby"producingacidification .re-Ii actionproducts in the liquidlstate free of solld precipiI tates.

3. A process for the conversion of hexachloroacetone intotrichloroacetic acid land chloroformwhich comprises intimately`rnixing'as 4the sole reactants hexachloroacetone with an aqueoussolution of sodium hydroxide at a temperature below 60 C. for asufficient length of timev to effect scission `of the hexachloroacetonemolecule and reaction withthe aqueous sodium hydroxide fin theproportion `of one mol hexachloroacetone to about one mol of sodiumhydroxide toproduce an aqueous`solu r tion of sodium trichloroacetone.and.chloroform, and

acidifying the mixture of the aqueouslsolution of sodiumtrichloroacetate and chloroform by reaction at a Atem-` time to effectscission of the hexachloroacetone molecule andreaction 'with the aqueouspotassium-hydroxidein the proportion of one mol hexachloroacetone toabout one mol of potassium hydroxide to produce an aqueous solution ofpotassium trichloroacetate and chloroform, and acidifying the mixture ofthe aqueous solution of potassium trichloroacetate and chloroform byreaction at a temperature below C. with excess sulfuric acid in anamount sufficient to liberate trichloroacetic acid and form potassiumbisulfate thereby producing acidication reaction products in the liquidstate free of solid precipitates.

5. A process for the conversion of hexachloroacetone intotrichloroacetic acid and chloroform which com prises intimately mixingas the sole reactants hexachloroacetone with an aqueous solution of sodaash at a temperature below 60 C. for a sufficient length of time toeffect scission of the hexachloroacetone molecule and reaction with theaqueous soda ash solution in the proportion of one mol hexachloroacetoneto about one mol equivalent of soda ash to produce sodiumtrichloroacetate and chloroform and acidifying the mixture of aqueoussolution of sodium trichloroacetate and chloroform by reaction at atemperature below 60 C. with aqueous no at `a temperature below/60 C.for a Vsufficient length `of 6. A process '.forhthe `preparation oftrichloroacetic acid from a metal saltof trichloroacetic acid whichcomprises admixing an` aqueous solution of a metal salt oftrichloroacetic acid,y a liquid solvent'characterized .by beingimmiscible with water and miscible with trichlorof acetic acid, landxanexcess of sulfuric acid in an amounty sufficient toliberatetrichloroacetic yacid and form a `bi-l sulfate thereby producingacidification reaction products in kthe liquid state .free of 'solidprecipitate, settling the reaction products to permit separation into alayer of aqueous bisulfate solutionand a layer of trichloroacetic`acid-solvent,i separating the trichloroacetic acid-solvent layer fromthe reaction products and'recovering the trichloroaceticacid.

7. A process `for the preparation of trichloroacetic acid :from sodium.trichloroacetate which comprises admixing an aqueous 4solution of sodiumtrichloroacetate, chloroform and an excess of sulfuric acid, maintainingthemixture at a temperature below 60 C. for a sui- 'f cient length `oftime to liberate `trichloroacetic acid and form sodium bisulfate therebyproducing acidification reactionv productsin `the liquid state free ofsolid precipitates,` settling the reaction mixture to form an upper ilayer `of .an aqueous solution of sodium bisulfate and a lower -layer oftrichloroacetic acid-chloroform, separating said :lower layer fromfthereaction products, vaporizing. ythe chloroform from` the trichloroaceticacidchloroform: mixture and recovering the trichloroacetic acid.V

8. A process for the preparation of trichloroacetic acid` from:potassium trichloroacetate which comprisesA admixingtan .aqueoussolutionof potassium trichloroacetate,r chloroform and an yexcess ofsulfuric acid,` maintaining .the mixture at a temperature below 60 C.for a sufficient llength `of time to liberate trichloroacetic acid andform `potassiuml bisulfate thereby Vproducing acidification `reactionproducts in the liquid state free of solid precipitateassettling` thereaction mixtureV toform an upper flayer of 4anfaqueous solution ofpotassium bisulfate and .a lower layer Vof trichloroaceticacid-chloroform, sepf arating'said lower vlayer from the reactionproducts, vaporizinglfthemchloroform from the trichloroaceticacidchloroform"mixture andrecovering the trichloroacetic acid;

9. A process for-the 'conversion of hexachloroacetone-intoftrichloroacetic 'acid` and chloroform which comprisesadmixing iasthe sole reactants, hexachloroacetonel wit-han alkaline yaqueoussolution of an alkali metal compoundl fora suicient length of time toeffect scissionof the2hexachloroacetone7 molecule and reaction with theaqueous .alkali metal compound in the proportion of `one mol.hexachloroacetone to `about one mol equivalent of alkali".metalcompound-'to produce an aqueous solution offa metal saltvoftrichloroacetic acid and chloroform, acidifyingwthe aqueous solution ofmetal salt of trichloroaceticacid in thepresence of said chloroformproductiby reaction 'withexcess sulfuric .acid in an vamountsufiicientvto `.liberate Vtrichloroacetic acid and form a bisulfate.thereby `producing acidification reaction products inthe liquidfstatefree of solid precipitates, settling the acidification reaction productsto form an upper layerof 'i aqueous bisulfate solution and a lower layerof trichloroacetic acicl-chloroform, separating the lower layer oftrichloroacetic acid-chloroform from the reaction products, vaporizingthe chloroform from the trichloroacetic acidchloroform mixture,condensing and collecting the vaporzed chloroform and recovering lthetrichloroacetic aci l0. A process for the conversion ofhexachloroacetone into trichloroacetic acid and chloroform whichcomprises admixing as the sole reactants hexachloroacetone with anaqueous solution of sodium hydroxide, maintaining the mixture at atemperature within the range of 0 C. to 60 C. for a suflicient length oftime to effect scission of the hexachloroacetone molecule and reactionwith the aqueous sodium hydroxide solution in the proportion of one molhexachloroacetone to about one mol of sodium hydroxide to produce anaqueous solution of sodium trichloroacetate and chloroform, acidifyingthe aqueous solution of sodium trichloroacetate in the presence of thechloroform product with sulfuric acid in the proportion of about 1 molof sulfuric acid to l mol of sodium trichloroacetate, maintaining themixture at a temperature below 60 C. for a sufficient length of time toliberate trichloroacetic acid and form sodium bisulfate, settling theacidification reaction products to form an upper layer of aqueous sodiumbisulfate and a lower layer of trichloroacetic acid-chloroform,separating the lower layer from the acidification reaction products,vaporizing the chloroform from the trichloroacetic acidchloroformmixture and recovering the chloroform and trichloroacetic acid asseparate products.

11. A process for the conversion of hexachloroacetone intotrichloroacetic acid and chloroform which comprises admixing as the solereactants hexachloroacetone with an aqueous solution of potassiumhydroxide, maintaining the mixture at a temperature within the range ofC. to 60 C. for a sufficient length of time to effect scission 0f thehexachloroacetone molecule and reaction with the aqueous potassiumhydroxide solution in the proportion of one mol hexachloroacetone toabout one mol of potassium hydroxide to produce an aqueous solution ofpotassium trichloroacetate and chloroform, acidifying the aqueoussolution of potassium trichloroacetate in the presence of the chloroformproduct with sulfuric acid in the proportion of about l mol of sulfuricacid to l mol of potassium trichloroacetate, maintaining the mixture ata temperature below 60 C. for a sufficient length of time to liberatetrichloroacctic acid and form potassium bisulfate, settling theacidification reaction products to form an upper layer of aqueouspotassium bisulfate and a lower layer of trichloroaceticacid-chloroform, separating the lower layer from the acidificationreaction products, vaporizing the chloroform from the trichloroaceticacid-chloroform mixture and recovering the chloroform andtrichloroacetic acid as separate products.

12. A process for the conversion of hexachloroacetone intotrichloroacetic acid and chloroform which comprises admixing as the solereactants hexachloroacetone with an aqueous solution of sodiumhydroxide, maintaining the mixture at a temperature within the range of0 C. to 60 C. for a sufficient length of time to effect scission of thehexachloroacetone molecule and reaction with the aqueous sodiumhydroxide solution in the proportion of one mol hexachloroacetone toabout one mol of sodium hydroxide to produce an aqueous solution ofsodium trichloroacetate and chloroform, acidifying the aqueous solutionof sodium trichloroacetate in the presence of the chloroform productwith sulfuric acid in the proportion of about 1 mol of sulfuric acid tol mol of sodium trichloroacetate, maintaining the mixture at atemperature below 60 C. for a sufficient length of time to liberatetrichloroacetic acid and form sodium bisulfate, settling theacidification reaction products to form an upper layer of aqueous sodiumbisulfate and a lower layer of trichloroacetic acid-chloroform,separating the lower layer from the acidification reaction products,vaporizing chloroform from the trichloroacetic acid-chloroform mixture,condensing the chloroform vapors, returning a portion of the chloroformcondensate in contact with the upper layer of aqueous sodium bisulfatesolution to extract therefrom additional trichloroacetic acid,separating the trichloroacetic acid-chloroform extract after contactwith the aqueous sodium bisulfate solution and vaporizing chloroformfrom the trichloroacetic acidchloroform extract.

13. A process for the conversion of hexachloroacetone which comprisesadmixing as the sole reactants hexachloroacetone with an alkalineaqueous solution of an alkali metal compound, maintaining the mixture ata temperature within the range of 0 C. to about 60 C. for a sufiicientlength of time to effect scission of the hexachloroacetone molecule andreaction with the aqueous solution of alkali metal compound in theproportion of one mol hexachloroacetone to about one mol equivalent ofalkali metal compound to produce a metal salt of trichloroacetic acidand chloroform.

14. A process for the conversion of hexachloroacetone which comprisesadmixing as the sole reactants hexachloroacetone with an aqueoussolution of sodium hydroxide and maintaining the mixture at atemperature Within the range of 0 C. to 60 C. for a sufficient length oftime to effect scission of the hexachloroacetone molecule and reactionwith the sodium hydroxide in the proportion of one mol hexachloroacetoneto about one mol of sodium hydroxide to produce sodium trichloroacetateand chloroform.

15. A process for the conversion of hexachloroacetone which comprisesadmixing as the sole reactants hexachloroacetone with an aqueoussolution of potassium hydroxide and maintaining the mixture at atemperature within the range of 0 C. to 60 C. for a suicient length oftime to effect scission of the hexachloroacetone molecule and reactionwith the potassium hydroxide in the proportion of one molehexachloroacetone to about one mol of potassium hydroxide to producepotassium trichloroacetate and chloroform.

16. A process for the conversion of hexachloroacetone which comprisesadmixing as the sole reactants hexachloroacetone with an aqueoussolution of soda ash and maintaining the mixture for a sufficient lengthof time to effect scission of the hexachloroacetone molecule andreaction with the aqueous solution of soda ash in the proportion of onemol hexachloroacetone to about one mol equivalent of soda ash to producesodium trichloroacetate and chloroform.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,371,757 Henne Mar. 20, 1945 2,414,706 Babcock et al. Jan.2l, 1947 2,442,995 Coffman June 8, 1948 2,480,467 Haworth et al. Aug.30, 1949 FOREIGN PATENTS Number Country Date 577,481 Great Britain May20, 1946 OTHER REFERENCES Cloez, Ann. de Chim. et Phys., 6e Serie, vol.9, pp. 199-205 (1886).

Brochet and others, Beilstein (Handbuch, 4th ed.) vol. 1, pp. 656-7(1918). (lgigltein (Handbuch 4th ed.), vol. I, 1st sup., p. 345

Richter, Organic Chem., vol. l, page 291 (3d Eng. Ed.).

1. A PROCESS FOR THE CONVERSION OF HEXACHLOROACETONE INTOTRICHLOROACETIC ACID AND CHLOROFORM WHICH COMPRISES ADMIXING AS THE SOLEREACTANTS HEXACHLOROACETONE WITH AN AQUEOUS ALKALINE SOLUTION OF ANALKALI METAL COMPOUND AT A TEMPERATURE BELOW ABOUT 60* C. FOR ASUFFICIENT LENGTH OF TIME TO EFFECT SCISSION OF THE HEXACHLOROACETONEMOLECULE AND REACTION WITH THE ALKALI METAL COMPOUND IN THE PROPORTIONOF ONE MOL HEXACHLOROACETONE TO ABOUT ONE MOL EQUIVALENT OF ALKALI METALCOMPOUND TO PRODUCE A METAL SALT OF TRICHLOROACETIC ACID AND CHLOROFORMAND ACIDIFYING THE MIXTURE OF THE METAL SALT OF TRICHLOROACETIC ACID ANDCHLOROFORM BY REACTION WITH EXCESS SULFURIC ACID IN AN AMOUNT SUFFICIENTTO LIBERATE TRICHLOROACETIC ACID AND FORM A BISULFATE THEREBY PRODUCINGACIDIFICATION REACTION PRODUCTS IN THE LIQUID STATE FREE OF SOLIDPRECIPITATES.